So this is what the LORD says about the king of Assyria:
The LORD says the king of Assyria will not come into this city, shoot an arrow there, or advance against it.
It states the military outcome in direct terms.
20Then Isaiah son of Amoz sent a message to Hezekiah: “This is what the LORD, the God of Israel, says: I have heard your prayer concerning Sennacherib king of Assyria. 21This is the word that the LORD has spoken against him: 22Whom have you taunted and blasphemed? 23Through your servants you have taunted the Lord, 24I have dug wells 25Have you not heard? 26Therefore their inhabitants, devoid of power, 27But I know your sitting down, 28Because your rage and arrogance against Me 29And this will be a sign to you, O Hezekiah: 30And the surviving remnant of the house of Judah 31For a remnant will go forth from Jerusalem, 32So this is what the LORD says about the king of Assyria: 33He will go back the way he came, 34I will defend this city